Vacuum tube device



Feb. 27, 1934. w D 1,949,396

VACUUM TUBE DEVICE Filed Nov. 22, 1924 zzj zaf"

M BY ATTORNEY Patented Feb. 27, 1934 NETED STATES PATET r ce VACUUM TUBE DEVICE Application November 22, 1924 Serial No. 751,509

Claims.

My invention relates to thermionic discharge devices and particularly to thermionic discharge devices adapted for the translation of large powers.

An object of my invention is to provide a thermionic discharge device adapted for the utilization of greater power than devices of the prior art.

Another object of my invention is to provide 'a thermionic discharge device having a high mutual conductance.

Another object of my invention is to provide a thermionic discharge device having a minimum impedance at high powers.

Another object of my invention is to provide a thermionic discharge device adapted for artificial cooling.

Another object of my invention is to produce a thermionic discharge device having a segmental filamentary cathode, each segment being surrounded by a concentric grid structure.

In the prior construction of thermionic discharge devices, the energy which could be translated by such devices has been rigorously limited by the ability of the device to dissipate as heat the energy loss which always occurs in translation devices. In the prior art, thermionic discharge devices had metal electrodes mounted within an evacuated glass container and the rate iof heat dissipation was limited bythe rate of heat dissipation from the anode to and through the glass. If the device was forced to translate energy at excessively high rates, the plate electrode could readfly be fused and destroyed. Atitempts have, therefore, been made to construct a device in which the anode material is made a portion of the container wall, whereby its inner surface is adapted to receive an electron stream and its outer surface is adapted to the applica- 1tion oi artificial cooling media, whereby overheating and fusion are prevented.

In the construction of such devices, difficulty has been experienced in obtaining a cathode structure suiiiciently large to provide the necessary electron stream, without, at the same time, spacing both grid and plate at such great distance as to introduce an undesirably large space charge eifect and making the ratio of spacing from cathode to grid and grid to plate, such that the device had an undesirably low amplification factor, thereby requiring undesirably high grid potentials to produce oscillation. Likewise it was found difficult to provide a sufficiently small grid structure so that its charging current was of a sufilciently small value and such that the mutual (Cl. 250-z7.5)

conductance of the device was sufiiciently high.

My invention provides a plurality of straight filament segments and a supporting structure therefor. The straight segmental filaments are surrounded by relatively very small grid members which in turn are surrounded by very closely placed anode members. This structure is a duplex or double-barrelled construction. By this means, it becomes possible to attain the objects previously mentioned.

Other objects and structural details of my invention will be apparent from the following description when read in connection with the accompan ing drawing, wherein:

Figure l is a longitudinal sectional view of an embodiment of my device,

Fig. 2 is a View thereof in transverse section on the lines IIlI of Fig. 1,

Fig. 3 is a perspective view of a portion of the anode structure of my device, and

Fig. 4 is a view in transverse section taken on line IVIV of Fig. 1.

Referring to the drawing, 1 is an anode structure, which may be described as double-barreled, or multi-lobular, or multi-tubular, or foliated. It consists of a metal member, preferably cylindrical at its ends, with line indentations upon opposite sides which may almost, or entirely, meet and produce a structure equivalent to two tubes, side-by-side, preferably connected by a narrow crevice parallel to the axes of the tubes and the axis of the device. The ends of. the anode structure 1 are thinned in order to produce an edge seal. To the ends are sealed glass closures 2 and 3 forming seals 4 and 5. The closure 3 is provided with a re-entrant portion 6 and a press 7 thereon through which are inserted cathode leads 8 and 9. The closure 2 is provided with indentations 11 and projections 12 thereon between which is mounted an insulating disk member 14 having perforations therethrough.

Filaments l5 and 16 are attached at one end respectively to lead wires 8 and 9. A connecting and supporting member 17 inserted through holes in the plate 14 is provided to which the ends of filaments 15 and 16 are attached. Springs 18 placed thereabout provide suitable tension for the filaments 15 and 16.

Grid members 20 and 21 are provided surrounding filaments 15 and 16. These grid members consist of helices of wires having spaced turns. Supporting wires 22 are provided lengthwise within the helices and attached thereto as strengthening, supporting and positioning means. Conjugate ends of the wires 22 are inserted in holes supports 11 and 12 in plate 14. The other ends are attached to a collar 23 which surrounds press 6 and is positioned thereby. A tubulature 24 is provided in the closure 3 which is sealed off at the completion of the exhaustion of the device. A grid lead is connected to collar 23 and to wires 22.

In the construction of my device, reentrant portion 6, press 7 and lead wires 8 and 9 are prepared as is customary in the prior art. The anode structure 1 is prepared by cleaning the excess oxide and grease therefrom. The ends thereof at the thinned edges are beaded with glass which is caused to wet the surface of the metal in the manner of the prior art. To this coating of glass are attached closures 2 and 3.

Filament wires 15 and 16 are attached to lead wires 8 and 9 preferably by welding and the grid structure 20 and 21 and its supporting wires and collar 23 are positioned upon portion 6. This structure, which may be called the mount, may then be inserted Within the anode structure and allowed to pass as far therethrough as possible. This permits the other ends of filaments 15 and 16 to project sufficiently far from the other end of anode 1 to permit the attaching thereto or" connector 17 while positioned within plate or disc 14. The tube comprising closure 2 may then be sealed to the glass beading upon the end of anode 1.

The flare oi the mount, made from tube 6, may then be sealed to the tube 3 and the lower ends of the grids and filaments positioned properly with respect to the anode structure 1. The tube 2 may then be heated and the proper indentures and formed therein to support and position the other ends of filaments 15 and 16 and grid structures 20 and 21. The end of the tube 2 may then be closed by sealing as is done in the art. During the operation of sealing the mount formed about tube 6 into tube 3, provision may be made for the insertion of tubulature 24 and grid lead 25.

The device may then be evacuated by carefully pumping, baking and treating in the manner well known in the prior art, at the close of which treatment it may be sealed ofi.

By means of the construction as described, I am enabled to obtain a thermionic discharge device having a sufiiciently large cathode to give a desirably large electron stream, without, at the same time, producing a structure so large as to require an undesirably great separation between cathode and anode and between cathode and grid. The construction likewise embodies a relatively small grid structure and permits the utilization of relatively large powers, which may be measured in numbers of kilowatts, since its outer sur face is exposed to artificial cooling and since the spacing between cathode and anode is relatively small. Also, the small spacing, advantageous position of the grid, and large electron stream enable me to produce a device having a desirably high mutual conductivity.

While I have shown only one embodiment of my invention in the accompanying drawing, it is capable of various changes and modifications without departing from the spirit thereof, and it is desired, therefore, that only such limitations shall be placed thereon as are imposed by the prior art or indicated in the appended claims.

I claim as my invention:

1. An electron-discharge-tube device comprising a plurality of cathode sections, a plurality of anode sections, each. anode section surrounding a cathode section and embracing over 180 oi the angular space about said cathode and constituting therewith a substantially distinct electrode compartment having an outer metallic wall portion, and an insulating means joined to the metallic wall portions of said electrode compart ments and constituting therewith a hermetic enclosure common to a plurality of said compartments.

2. An electron-discharge device comprising a plurality of tubular anode portions constituting substantially distinct and substantially enclosing compartments, insulating closure means joined to said anode portions and constituting therewith a common enclosure, cathode elements dis posed in said tubular anode portions, and grid members associated with said cathode members, said cathode and grid members being supported on said closure means.

3. An electron-discharge device comprising an evacuated envelope, anode means comprising a plurality of lobular metallic portions constituting wall sections of said envelope to permit external cooling of the same, cathode members disposed substantially in the center of substantially enclosing compartments constituted by said lobular portions, grid members arranged substantially concentrically with said cathode members, and means for insulatingly supporting said cathode and grid members within said envelope.

4. A thermionic discharge device comprising a multi-lobular anode, vitreous closure means joined to said anode and constituting therewith a hermetic envelope, said means including a reentrant portion, lead wires through said portion, a control electrode comprising a plurality of tubular members within the lobes of said anode, a collar positioned upon said re-entrantportion, supporting means attaching said control electrode to said collar, and a sectional cathode member therewithin, and connected to said lead wires.

5. An electric discharge device comprising an 5 elongated container having an anode and a cathode, supporting means for one end of said cathode being fixed to one end of said container and fixedly supporting said cathode therefrom, a member of insulating material supported by the 1'20 other end of the container and having an opening therethrough, cathode supporting means for the other end of the cathode extending through said opening and resiliently supported on said member of insulating material.

6. An electric discharge device comprising an elongated container having an anode, grid and cathode, supporting means for one end of said cathode and supporting means for one end of said grid being fixed to one end of said container '3 and fixedly supporting said cathode and said grid therefrom, a member of insulating material supported by the other end of the container and having openings therethrough, supporting means for the other end of the cathode and grid supporting 5 means for the other end of the grid extending through said openings whereby longitudinal extension of said cathode and grid is permitted.

I. An electric discharge device comprising an elongated container having an anode, grid and 4 cathode, supporting means for one end of said cathode and supporting means for one end of said grid being fixed to one end of said container and fixedly supporting said cathode and said grid therefrom, a member of insulating material sup- 1,155 ported by the other end of the container and having openings therethrough, supporting means for the other end of the cathode and grid supporting means for the other end of the grid extending through said openings whereby longitudinal extension of said cathode and grid is permitted, said cathode being resiliently supported from said member of insulating material.

8. An electron discharge device comprising an elongated container having an anode, grid and cathode, said anode being fixedly mounted in said container, supporting means for one end of said cathode and supporting means for said grid being fixed to one end of said container and fixedly supporting said cathode and grid therefrom, a member of insulating material supported by the other end of the container and having openings therethrough, supporting means for the other end of the cathode and grid supporting means for the other end of the grid extending through said openings in sliding engagement therewith whereby longitudinal extension of the cathode and grid is permitted without substantial variation in the lateral spacing from said fixedly mounted anode.

9. An electric discharge device comprising a double-barreled anode structure having said barrels side-by-side with a narrow crevice parallel to the axis of said barrels connecting the two barrels, glass closure members sealed to each end of said double-barreled anode structure, one of said closure members provided with a press, lead wires through said press, a cathode structure comprising a filament extending through each of the barrels of said anode structure, one end of said filaments being connected to said lead wires, an insulating disk member mounted on the other of said closure members and having openings therethrough, supporting means for the other end of said filaments extending through said openings and resiliently supported on said insulating disk member.

10. An electrical discharge device comprising an elongated container having an anode and cathode, supporting means for one end of said cathode being fixed to one end of said container and fixedly supporting said cathode therefrom, a constricted portion at the other end of said container, a member of insulating material supported by said constricted portion and having an opening therethrough and cathode supporting means for the other end of said cathode passing through the opening in said member of insulating material. WALLACE G. WADE. 

